Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    DHCPD6 hands out wrong subnet

    Scheduled Pinned Locked Moved IPv6
    3 Posts 3 Posters 1.5k Views
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • JeGrJ
      JeGr LAYER 8 Moderator
      last edited by

      Hi all,

      I have a confusing problem as I have a /64 v6 subnet configured on LAN side of my pfSense and configured DHCPD6 for dynamic and static leases. SLAAC on clients work fine, they generate their mac-based IP and a privacy IP with /64 subnet just fine. But as I tried configuring some servers or NAS to use DHCP instead so I can manage their IP addresses through pfSense and the static lease list, the DHCP6 Server hands out those addresses - but with /128 as the subnet instead of /64.

      Is there anywhere I have to configure the /64 netmask in addition to LAN interface? DHCP6 server config page shows:

      DHCPv6 Server Enable (checked)

      Subnet 2001:xxx:xxx:xxx::
      Subnet mask 64 bits
      Available range 2001:xxx:xxx:xxx:: - 2001:xxx:xxx:xxx:ffff:ffff:ffff:ffff

      Range: 2001:xxx:xxx:xxx:feed:: To 2001:xxx:xxx:xxx:feed:ffff:ffff:ffff

      So seems pretty straightforward and as DHCPv6 recognizes the subnet mask with /64, I don't get it why it hands out addresses as /128.

      Greets

      Don't forget to upvote 👍 those who kindly offered their time and brainpower to help you!

      If you're interested, I'm available to discuss details of German-speaking paid support (for companies) if needed.

      1 Reply Last reply Reply Quote 0
      • H
        hda
        last edited by

        @JeGr:

        So seems pretty straightforward and as DHCPv6 recognizes the subnet mask with /64, I don't get it why it hands out addresses as /128.

        If ((2001:babe:face:5:4:3:2:1) AND (ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff) = 2001:babe:face:5:4:3:2:1) Then
        host is unique and has its ID on internet like such a number, as a /128

        If ((2001:babe:face:5:4:3:2:1) AND (ffff:ffff:ffff:ffff:0:0:0:0) = 2001:babe:face:5:0:0:0:0) Then
        no route to that host

        1 Reply Last reply Reply Quote 0
        • R
          razzfazz
          last edited by

          How do you enable both DHCP-PD and the DHCP6 server? Any interfaces configures as "track interface" (i.e., use delegated prefix) don't even show up in the DHCP6 server configuration for me at all…

          1 Reply Last reply Reply Quote 0
          • First post
            Last post
          Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.